In 1920, the New York-New Jersey Trail Conference was formed when local hiking clubs gathered to plan a system of marked hiking trails to make Harriman-Bear Mountain State park more accessible to the public. In this same park, Trail Conference founders constructed and opened the first section of the Appalachian Trail in 1923. During the 1930s, more trails were built and a system of trail maintenance was developed, giving each hiking club a share of the responsibility.
By the time the 1970s came, the Trail Conference began to do more than just maintain trails, e.g. begin to publish hiking maps beginning with Bear Mountain/Harriman State Parks.
In the late 1970s and early 1980s, the Trail Conference moved the AT off of roads and onto NPS property purchased to permanently protect it. It marked the beginning of expansion of the number of miles of trails the Trail Conference maintained.
As of 2008, this maintenance network covers 1,700 miles of foot trails from the Delaware Water Gap north to beyond the Catskills. The Trail Conference is also involved with other not-for-profits and governmental units to ensure that the public has access to hiking trails.